The present invention relates to a method of and apparatus for attaching a suture to an operating needle.
Various apparatus of the kind referred to above are known in which one end of a suture is inserted into a bore formed in a proximal end of an operating needle and extending along an axis thereof, and the end of the operating needle is clamped between recesses respectively formed in forward ends of respective movable and fixed staking dies and is staked thereby, to attach the suture to the operating needle. The fixed staking die is supported on a staking base in immovable relation thereto, and the movable staking die is also supported on the staking base for movement toward and away from the fixed staking die. The known apparatuses are divided broadly into three types.
First one of the above three types is an apparatus which utilizes human power. Specifically, the apparatus is arranged such that a foot pedal is operated to move the movable staking die toward the fixed staking die through a linkage. The second type of apparatus is arranged such that a foot pedal or a foot switch is operated to actuate a hydraulic cylinder, to thereby cause the force from the hydraulic cylinder to move the movable staking die toward the fixed staking die. The third type of apparatus is one developed by the inventor of the present application, in which the movable staking die is moved by a motor. Typical apparatus of such third type is disclosed in U.S. Pat. No. 4,306,443 issued to Matsutani on Dec. 22, 1981. In all of the apparatuses of the types referred to above, the staking base is fixedly mounted on a table.
There are many kinds of operating needles, and the proximal ends of the respective needs are various in outer diameter, for example. In order to perform an optimum staking, it is necessary to change the radii of the recesses in the respective movable and fixed staking dies, depending upon the outer diameters of the proximal ends of the needles.
In all of the apparatuses of the types described above, the staking base is fixed to the table and, accordingly, if it is desired to stake a different kind of needles, it is required to remove the fixed and movable staking dies from the staking base, and to substitute therefor another fixed and movable staking dies. Such substituting or replacing operation, however, is very troublesome.
In addition, if circumstances require, it is necessary to change or vary the staking force in accordance with the outer diameters of the proximal ends of the needles and the diameters of the sutures. However, the staking force has to be re-adjusted each time the types of the needle to be staked are changed. This is troublesome and requires considerable skill.
Thus, the known apparatuses cannot be said to be suitable for a multiple-kind and small-quantity production.